Vmem Vmod for Asus V9999GT (6800GT) 128MB needed

[zombie]

hello,
i searching for a easy to solder Vmem Vmod for this videocard. Anybody know a guide or Infos how it works ? I Only can found Vgpu Vmods

Here this card:
http://www.ocer.net/article/a_upload/1103796908_4-.jpg
http://www.web-upload.de/data/media/21/2.jpg

thanks for help

[Frostologe]

I'm searching a Vmem mod too. Doesn't anyone know one. The Asus layout of this card is very strange, so i can't really do the normal GT Vmem mod.
Has anyone other good mods for this card???

[SikaRippa]

I am not sure if I can help, but if you provide following information we will see...

Could you tell ALL marking codes of the following chips:

- 3 chips top of the card (right side of the card = figure) having 8 leads
- 2 chips bottom of the card (left side of the card = figure) having 8 leads
- 1 chip bottom of the card (left side of the card = figure) having 14 leads

Could you measure DC-voltages of the test points ?

[Frostologe]

Here we go. I hope I got the right chips.
- 2x 9926M425142 and CM8562PI46114.140412C0
- I can't really identify the codes on the chips.
- ISL6522CB P436CLR

[SikaRippa]

Here we go. I hope I got the right chips.
- 2x 9926M425142 and CM8562PI46114.140412C0
- I can't really identify the codes on the chips.
- ISL6522CB P436CLR

I took a brief look about those datasheet. ISL6522CB is a switching regulator which can provide ONE output voltage and this is a little bit different arrangement compared to e.g. some other 6800-cards. I do not know if this regulator would make the core or memory voltage. If that one is for core (??) the two chip having 8 leads (bottom of the card) ARE important. So, no way to get codes for those ??

Could you specify ALL markings of those big yellow capacitors and also four brown caps (all located at the top of card) ? That could be helpful to identify which nodes have mem-voltage and which one have core voltage..

--

Could you measure voltages from test points TP1 -TP4 (see top figure) ?

[Frostologe]

Hmm i have big problems reading the codes on the chips.
Can anyone helps us with that?

[SikaRippa]

Hmm i have big problems reading the codes on the chips.
Can anyone helps us with that?

Do you have the card yourself ? Are the marking too poor quality to read ?


How about those capacitor markings ? Since, IF ISL6522CB generates memory voltage there is no need to find out those chip markings..

[Frostologe]

Yeah I have it myself, but i can't read it the quality is too bad.
Did you take a look at those pdfs??

[SikaRippa]

Yeah I have it myself, but i can't read it the quality is too bad.
Did you take a look at those pdfs??

Sorry, I was doing ~n*2 things in the same time I missed the first one

--

But great work with measurements !!

I SUPPOSE that:

TP1 = Vcore (?, what it should be for GT )
TP2 = Vmem
TP3 = VTT/VREF
TP4 = could it be ..... GND

To be absolute sure could you measure resistance between:

- TP2 and positive terminal of 'brown' capacitors in the middle (6.3 V 820 uF)
- TP3 and all terminals with 'CM8652' (should be short between two?). If no short then using TP1..

Are there any manufacturing codes for those '6.3 V 820 uF'-capacitors ?

[Frostologe]

I don't think that this is the manufacturing code of the brown capacitors but maybe it helps you a little bit: (M)105°C 4(7) OB /and the 2 in the middle OA
I measured resistance and get values of only 69.5 Ohm on both brown capacitors in the middle, could that be realistic??
With TP1 and CM8652 i got ~97Ohm on the 2 terminals at the top of the chip on the right side and on the second of the left side. On the first one at the right side I got 323 Ohm.
Take a look at the pdf.

[SikaRippa]

I don't think that this is the manufacturing code of the brown capacitors but maybe it helps you a little bit: (M)105°C 4(7) OB /and the 2 in the middle OA
I measured resistance and get values of only 69.5 Ohm on both brown capacitors in the middle, could that be realistic??
With TP1 and CM8652 i got ~97Ohm on the 2 terminals at the top of the chip on the right side and on the second of the left side. On the first one at the right side I got 323 Ohm.
Take a look at the pdf.

So, no manufacuturer lebel (i.e. Nichicon, Panasonic etc) for caps ?

--

I summarize those measurements, please comment if wrong:

V(TP1-GND) = 1.35 V
V(TP2-GND) = 2.67 V
V(TP3-GND) = 1.33 V
V(TP4-GND) = 0 V

R(Brown caps) = 69.5 Ohm (between +/- terminals ?)
R(TP1-CM8652.terminals) = 323, 97,97, - (left) 97,97, - , - (right)

I think we would need at least following values to proceed (to find out which circuitry generates vmem):

R(TP3-CM8652.terminals) =
R(TP2-Brown caps + terminals)=

--

You might want try yourself identify the components related to 'ISL6522CB' switching regulator (easily tracked with a multimeter). I think that the two yellow caps are for Vcore (since only 2.5 V rating !!), the inductor right to them is connected with those and two power-transistors (located top of those) control inductor & yellow caps (=output filter). The schematic should be similar to shown here:

http://www.intersil.com/data/fn/fn9030.pdf

[Frostologe]

I think i have to correct some values
R(Brown caps) = 61.9 Ohm (between +/- terminals )
R(TP1-CM8652.terminals) = -, 90,-, - (left) -,90, - , - (right)

R(Brown caps middle TP2-+) =62.7Ohm
R(TP3-CM8652.terminals) = -,-,0.2Ohm,-, (left) and -,-,-,0.2 Ohm (right)

[SikaRippa]

I think i have to correct some values
R(Brown caps) = 61.9 Ohm (between +/- terminals )
R(TP1-CM8652.terminals) = -, 90,-, - (left) -,90, - , - (right)

R(Brown caps middle TP2-+) =62.7Ohm
R(TP3-CM8652.terminals) = -,-,0.2Ohm,-, (left) and -,-,-,0.2 Ohm (right)

I am quite sure that those brown capacitors are used for Vmem filtering. The voltage rating is at correct range and the resistance is almost the same as I have measured with 6800le-card, which has exactly the same memories.

Is it possible to measure voltage between +/- terminals ? (or between + terminal and GND if easier). If you get value around 2.67 V this should be memory voltage (it is 2.72 V for 6800le).

--

If brown capacitors are for memory, the inductor top of it should be part of filter and the 9926M-chip could be power-mosfets driving regulator. Can you track with multimeter if there is a short between caps + pins and some node(s) of these chips After that you should guess (locate) the gate nodes for those chips and locate the driver chip = the core of the switching regulator (it should be one of those unknown chips..).

[SikaRippa]

By the way, I got an idea how might to be possible to get information about those chips.

I have found that very high quality photos be easily taken from PCB (i.e. graphic card) with a standard scanner. So, do you have a possibility to scan the bottom of your card (at least the area with THOSE chips) with maximum resolution (or at least with 600 dpi) ? I think that that kind of scanned image can be easily magnified with computer and/or manipulated with some program clear enough to identify those labels.

This could be also done by somebody other having V9999GT

[Frostologe]

Hmm maybe this could work but can't other owners of the card identify the 2 chips on the back???

[Pantacle]

zombie
chip ISL6522CB
This is core pancil voltmod

It is necessary to shade the resistor marked by a red arrow.
I use it. My core voltage is 1.49V.

[SikaRippa]

zombie
chip ISL6522CB
This is core pancil voltmod

It is necessary to shade the resistor marked by a red arrow.
I use it. My core voltage is 1.49V.

Fine .. so these chips bottom of the card have to be take care of Vmem.

Pantacle, Could you identify those labels ?

[Pantacle]

This is ISL6522C.
2ALL
Can you see my picture?
If not:
http://cp.people.overclockers.ru/cgi...ename=0786.JPG
Click on "Скачать файл 0786.gpj"
And
http://cp.people.overclockers.ru/cgi...ename=0791.JPG
Click on "Скачать файл 0791.gpj"

[SikaRippa]

This is ISL6522C.
2ALL
Can you see my picture?
If not:
http://cp.people.overclockers.ru/cgi...ename=0786.JPG
Click on "Скачать файл 0786.gpj"
And
http://cp.people.overclockers.ru/cgi...ename=0791.JPG
Click on "Скачать файл 0791.gpj"

I can not see pictures and those links give 'Cannot connect server'

[Pantacle]

SikaRippa
Do you know, where I can published my photo?

[SikaRippa]

SikaRippa
Do you know, where I can published my photo?

I have been used

http://www.imageshack.us/

.. easy to use. Only probmelm is limited figure size ~1MB. So, if you have a high resolution figure could you crop only interesting area

[Pantacle]

http://img169.echo.cx/my.php?image=07914dj.png
http://img169.echo.cx/my.php?image=07869nq.jpg
Ура!!!
Everything, has found, thanks. I spread mine photos. Enjoy!

[Frostologe]

Thank you.
hmm we have identify this chip already we need the other 2 chips on the back.
This is for Vcore we searching the chip for Vmem.
Can you identify the 2 other chips.

[Pantacle]

You speak about what chips? You Can note them on a photo?
P.S. I want Vmem too.

[SikaRippa]

You speak about what chips? You Can note them on a photo?
P.S. I want Vmem too.

The zoomed picture you posted was very good quality

--

The interesting chips can be located in this picture:

http://www.xtremesystems.org/forums/...chmentid=30639

.. where are two black lines at TOP part of the card. I do not know what chips generates Vmem, so could you post a picture area above white label.